<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>

</body>
<script type="text/javascript">
/* var i, myarray = [5, 6, 7];
for (i = myarray.length; i--) {
   // 使用myarray[i]做点什么
   console.log(i + "--" + myarray[i]);
} */

var myarray = [5, 6, 7],
i = myarray.length;
while(i--) {
// 使用myarray[i]做点什么
	console.log(i + "--" + myarray[i]);
}
</script>
</html>